How can I formally object to a neighbour's minor variance application in Ontario?

If you've received notice of a neighbour's minor variance application, or otherwise learn about one affecting a nearby property, you generally have the right to submit written comments to the committee of adjustment before the hearing, attend the hearing in person to speak directly to your concerns, or do both. Written submissions are worth putting in regardless of whether you plan to attend in person, since they become part of the record the committee considers even if you can't make the hearing date.

An effective objection focuses on the same legal test the committee itself has to apply, explaining specifically why the requested variance isn't minor in the context of the neighbourhood, why it's undesirable for the appropriate development of the land, or how it conflicts with the general intent of the zoning bylaw or official plan, rather than simply expressing general disapproval of the project or the applicant. If the variance is approved despite your objection and you believe the committee got the legal test wrong, you generally have a further right to appeal that decision to the Ontario Land Tribunal, within the applicable notice period after the decision is made.